<script>
import autoplay from '@/views/interestingComponents/carousel3d/mixins/autoplay'
import Controls from '@/views/interestingComponents/carousel3d/controls.vue'

function noop() {}

export default {
  name: 'Carousel3d',
  components: {
    Controls,
  },
  mixins: [autoplay],
  props: {
    count: {
      type: [Number, String],
      default: 0,
    },
    perspective: {
      type: [Number, String],
      default: 35,
    },
    display: {
      type: [Number, String],
      default: 5,
    },
    loop: {
      type: Boolean,
      default: true,
    },
    animationSpeed: {
      type: [Number, String],
      default: 500,
    },
    dir: {
      type: String,
      default: 'rtl',
    },
    width: {
      type: [Number, String],
      default: 360,
    },
    height: {
      type: [Number, String],
      default: 270,
    },
    border: {
      type: [Number, String],
      default: 1,
    },
    space: {
      type: [Number, String],
      default: 'auto',
    },
    startIndex: {
      type: [Number, String],
      default: 0,
    },
    clickable: {
      type: Boolean,
      default: true,
    },
    disable3d: {
      type: Boolean,
      default: false,
    },
    minSwipeDistance: {
      type: Number,
      default: 10,
    },
    inverseScaling: {
      type: [Number, String],
      default: 300,
    },
    controlsVisible: {
      type: Boolean,
      default: false,
    },
    controlsPrevHtml: {
      type: String,
      default: '&lsaquo;',
    },
    controlsNextHtml: {
      type: String,
      default: '&rsaquo;',
    },
    controlsWidth: {
      type: [String, Number],
      default: 50,
    },
    controlsHeight: {
      type: [String, Number],
      default: 50,
    },
    onLastSlide: {
      type: Function,
      default: noop,
    },
    onSlideChange: {
      type: Function,
      default: noop,
    },
    bias: {
      type: String,
      default: 'left',
    },
    onMainSlideClick: {
      type: Function,
      default: noop,
    },
    oneDirectional: {
      type: Boolean,
      default: false,
    },
    vertical: {
      type: Boolean,
    },
    direction: {
      type: String,
      default: 'left',
    },
  },
  data() {
    return {
      viewport: 0,
      currentIndex: 0,
      total: 0,
      dragOffsetX: 0,
      dragStartX: 0,
      dragOffsetY: 0,
      dragStartY: 0,
      mousedown: false,
      zIndex: 998,
      process_server: typeof window === 'undefined',
    }
  },
  computed: {
    isLastSlide() {
      return this.currentIndex === this.total - 1
    },
    isFirstSlide() {
      return this.currentIndex === 0
    },
    isNextPossible() {
      return !(!this.loop && this.isLastSlide)
    },
    isPrevPossible() {
      return !(!this.loop && this.isFirstSlide)
    },
    slideWidth() {
      const vw = this.viewport
      const sw = Number.parseInt(this.width) + Number.parseInt(this.border, 10) * 2

      return vw < sw && !this.process_server ? vw : sw
    },
    slideHeight() {
      const sw = Number.parseInt(this.width, 10) + Number.parseInt(this.border, 10) * 2
      const sh = Number.parseInt(Number.parseInt(this.height) + this.border * 2, 10)
      const ar = this.calculateAspectRatio(sw, sh)

      return this.slideWidth / ar
    },
    visible() {
      const v = this.display > this.total ? this.total : this.display
      return v
    },
    hasHiddenSlides() {
      return this.total > this.visible
    },
    leftIndices() {
      let n = (this.visible - 1) / 2

      n = this.bias.toLowerCase() === 'left' ? Math.ceil(n) : Math.floor(n)

      const indices = []

      for (let m = 1; m <= n; m++)
        indices.push(this.dir === 'ltr' ? (this.currentIndex + m) % this.total : (this.currentIndex - m) % this.total)

      return indices
    },
    rightIndices() {
      let n = (this.visible - 1) / 2

      n = this.bias.toLowerCase() === 'right' ? Math.ceil(n) : Math.floor(n)
      const indices = []

      for (let m = 1; m <= n; m++)
        indices.push(this.dir === 'ltr' ? (this.currentIndex - m) % this.total : (this.currentIndex + m) % this.total)

      return indices
    },
    leftOutIndex() {
      let n = (this.visible - 1) / 2

      n = this.bias.toLowerCase() === 'left' ? Math.ceil(n) : Math.floor(n)
      n++

      if (this.dir === 'ltr')
        return this.total - this.currentIndex - n <= 0 ? -Number.parseInt(this.total - this.currentIndex - n) : this.currentIndex + n
      else
        return this.currentIndex - n
    },
    rightOutIndex() {
      let n = (this.visible - 1) / 2

      n = this.bias.toLowerCase() === 'right' ? Math.ceil(n) : Math.floor(n)
      n++

      if (this.dir === 'ltr')
        return this.currentIndex - n
      else
        return this.total - this.currentIndex - n <= 0 ? -Number.parseInt(this.total - this.currentIndex - n, 10) : this.currentIndex + n
    },
  },
  watch: {
    count() {
      this.computeData()
    },
  },

  mounted() {
    if (!this.process_server) {
      this.computeData(true)
      this.attachMutationObserver()
      window.addEventListener('resize', this.setSize)

      if ('ontouchstart' in window) {
        this.$el.addEventListener('touchstart', this.handleMousedown)
        this.$el.addEventListener('touchend', this.handleMouseup)
        this.$el.addEventListener('touchmove', this.handleMousemove)
      }
      else {
        this.$el.addEventListener('mousedown', this.handleMousedown)
        this.$el.addEventListener('mouseup', this.handleMouseup)
        this.$el.addEventListener('mousemove', this.handleMousemove)
      }
    }
  },

  beforeUnmount() {
    if (!this.process_server) {
      this.detachMutationObserver()

      if ('ontouchstart' in window)
        this.$el.removeEventListener('touchmove', this.handleMousemove)
      else
        this.$el.removeEventListener('mousemove', this.handleMousemove)

      window.removeEventListener('resize', this.setSize)
    }
  },
  methods: {
    /**
     * Go to next slide
     */
    goNext() {
      if (this.isNextPossible)
        this.isLastSlide ? this.goSlide(0) : this.goSlide(this.currentIndex + 1)
    },
    /**
     * Go to previous slide
     */
    goPrev() {
      if (this.isPrevPossible)
        this.isFirstSlide ? this.goSlide(this.total - 1) : this.goSlide(this.currentIndex - 1)
    },
    /**
     * Go to slide
     * @param  {string} index of slide where to go
     */
    goSlide(index) {
      this.currentIndex = index < 0 || index > this.total - 1 ? 0 : index

      if (this.isLastSlide) {
        if (this.onLastSlide !== noop)
          console.warn('onLastSlide deprecated, please use @last-slide')

        this.onLastSlide(this.currentIndex)

        this.$emit('lastSlide', this.currentIndex)
      }

      this.$emit('beforeSlideChange', this.currentIndex)

      setTimeout(() => this.animationEnd(), this.animationSpeed)
    },
    /**
     * Go to slide far slide
     */
    goFar(index) {
      let diff = index === this.total - 1 && this.isFirstSlide ? -1 : index - this.currentIndex

      if (this.isLastSlide && index === 0)
        diff = 1

      const diff2 = diff < 0 ? -diff : diff
      let timeBuff = 0
      let i = 0

      while (i < diff2) {
        i += 1
        const timeout = diff2 === 1 ? 0 : timeBuff

        setTimeout(() => (diff < 0 ? this.goPrev(diff2) : this.goNext(diff2)), timeout)

        timeBuff += this.animationSpeed / diff2
      }
    },
    /**
     * Trigger actions when animation ends
     */
    animationEnd() {
      if (this.onSlideChange !== noop)
        console.warn('onSlideChange deprecated, please use @after-slide-change')

      this.onSlideChange(this.currentIndex)

      this.$emit('afterSlideChange', this.currentIndex)
    },
    /**
     * Trigger actions when mouse is released
     * @param  {object} e The event object
     */
    handleMouseup() {
      if (this.vertical)
        return

      this.mousedown = false
      this.dragOffsetX = 0
      this.dragOffsetY = 0
    },
    /**
     * Trigger actions when mouse is pressed
     * @param  {object} e The event object
     */
    handleMousedown(e) {
      if (this.vertical)
        return

      if (!e.touches)
        e.preventDefault()

      this.mousedown = true
      this.dragStartX = 'ontouchstart' in window ? e.touches[0].clientX : e.clientX
      this.dragStartY = 'ontouchstart' in window ? e.touches[0].clientY : e.clientY
    },
    /**
     * Trigger actions when mouse is pressed and then moved (mouse drag)
     * @param  {object} e The event object
     */
    handleMousemove(e) {
      if (this.vertical)
        return

      if (!this.mousedown)
        return

      const eventPosX = 'ontouchstart' in window ? e.touches[0].clientX : e.clientX
      const eventPosY = 'ontouchstart' in window ? e.touches[0].clientY : e.clientY
      const deltaX = this.dragStartX - eventPosX
      const deltaY = this.dragStartY - eventPosY

      this.dragOffsetX = deltaX
      this.dragOffsetY = deltaY

      // If the swipe is more significant on the Y axis, do not move the slides because this is a scroll gesture
      if (Math.abs(this.dragOffsetY) > Math.abs(this.dragOffsetX))
        return

      if (this.dragOffsetX > this.minSwipeDistance) {
        this.handleMouseup()
        this.goNext()
      }
      else if (this.dragOffsetX < -this.minSwipeDistance) {
        this.handleMouseup()
        this.goPrev()
      }
    },
    /**
     * A mutation observer is used to detect changes to the containing node
     * in order to keep the magnet container in sync with the height its reference node.
     */
    attachMutationObserver() {
      const MutationObserver = window.MutationObserver || window.WebKitMutationObserver || window.MozMutationObserver

      if (MutationObserver) {
        const config = {
          attributes: true,
          childList: true,
          characterData: true,
        }

        this.mutationObserver = new MutationObserver(() => {
          this.$nextTick(() => {
            this.computeData()
          })
        })

        if (this.$el)
          this.mutationObserver.observe(this.$el, config)
      }
    },

    detachMutationObserver() {
      if (this.mutationObserver)
        this.mutationObserver.disconnect()
    },
    /**
     * Get the number of slides
     * @return {number} Number of slides
     */
    getSlideCount() {
      const children = this.$slots.default()
      // console.log('>>>>>', children)
      if (children.length > 0)
        return children[0].children.length

      return 0
    },
    /**
     * Calculate slide with and keep defined aspect ratio
     * @return {number} Aspect ratio number
     */
    calculateAspectRatio(width, height) {
      return Math.min(width / height)
    },
    /**
     * Re-compute the number of slides and current slide
     */
    computeData(firstRun) {
      this.total = this.getSlideCount()
      if (firstRun || this.currentIndex >= this.total)
        this.currentIndex = Number.parseInt(this.startIndex) > this.total - 1 ? this.total - 1 : Number.parseInt(this.startIndex)

      this.viewport = this.$el.clientWidth
    },
    setSize() {
      this.$el.style.cssText += `height:${this.slideHeight}px;`
      this.$el.childNodes[0].style.cssText += `width:${this.slideWidth}px;` + ` height:${this.slideHeight}px;`
    },
  },
}
</script>

<template>
  <div class="carousel-3d-container" :style="{ height: `${slideHeight}px` }">
    <div class="carousel-3d-slider" :style="{ width: `${slideWidth}px`, height: `${slideHeight}px` }">
      <slot />
    </div>
    <Controls
      v-if="controlsVisible"
      :next-html="controlsNextHtml"
      :prev-html="controlsPrevHtml"
      :width="controlsWidth"
      :height="controlsHeight"
    />
  </div>
</template>

<style scoped>
.carousel-3d-container {
  min-height: 1px;
  width: 100%;
  position: relative;
  z-index: 0;
  overflow: hidden;
  margin: 20px auto;
  box-sizing: border-box;
}

.carousel-3d-slider {
  position: relative;
  margin: 0 auto;
  transform-style: preserve-3d;
  -webkit-perspective: 1000px;
  -moz-perspective: 1000px;
  perspective: 1000px;
}
</style>
